The board objectiv of the research is to provide reliable documentation of the infant's ability to recognize and comprehend the emotional expressions of others. It focuses specifically on two as yet unresolved questions: (1) Can yong infants detect the distinctive dynamic configurations relevant to adult's judgments of emotion? and (2) In what way do infants understand the "meaning" conveyed by emotional expression? With respect to Question 1, independent groups of 3-,5-, and 7-month-old infants will be required to recognize invariant expressive patterns (happy, sad, angry) displayed in videotaped episodes involving different perosn. Regarding Question 2, infants of 7,9-1/2 and 12 months plus any younger groups to have successfully discriminated in Study 1 will be tested on their ability to "match" a facial expression to (a) its appropriate gestural and vocalic accompaniments, (b) the behavior it typically signals, and (c) the circumstances that customarily evoke it. The research should have substantive impact on basic ussues in perceptual, socioemotional, and cognitive development as well as pragmatic implications for the mental health of children.